Recently, in the field of displays such as televisions including liquid crystal panels, 3D displays with which 3D images can be enjoyed have been developed in order to enhance performance. In such 3D displays, a stereoscopic image can be displayed by, for example, making the right eye of a viewer visually recognize an image for the right eye and making the left eye of the viewer visually recognize an image for the left eye.
Various 3D display methods for displaying 3D images can be used, and examples of the methods known as methods requiring no special eyeglasses include a lenticular lens method and a parallax barrier method.
As one of display methods for viewers to see 3D images with eyeglasses, a circularly polarized glasses method, for example, is known (see Patent Document 1, for example).
In a 3D display using the circularly polarized light glasses method, a retardation material is generally arranged on a display element for forming an image of a liquid crystal panel and the like. In this retardation material, two types of retardation regions having different retardation characteristics are regularly arranged each in plurality to constitute a retardation material that is patterned. In the present specification, a retardation material thus patterned in which a plurality of retardation regions having different retardation characteristics are arranged is called a patterned retardation material hereinafter.
The patterned retardation material can be fabricated by optically patterning a retardation substance including a polymerizable liquid crystal as described in Patent Document 2, for example. In the optical patterning of the retardation substance including a polymerizable liquid crystal, a photo-alignment technique known for forming an orientation material for a liquid crystal panel is used. More specifically, a coating made of a material having photo-alignment properties is provided on a substrate, and two types of polarized beams the polarization directions of which are different from each other are radiated on this coating. Thus, a photo-alignment film is obtained as an orientation material in which two types of liquid crystal alignment regions are formed and the directions of alignment control of liquid crystals in the regions are different from each other. Onto this photo-alignment film, a retardation substance containing a polymerizable liquid crystal in a solution state is applied to perform alignment of the polymerizable liquid crystal. Subsequently, the polymerizable liquid crystal thus aligned is cured to form a patterned retardation material.
As materials having photo-alignment properties that can be used in orientation material formation using a photo-alignment technique for liquid crystal panels, an acrylic resin and a polyimide resin, for example, are known having in a side chain thereof a photodimerized moiety such as cinnamoyl group and chalcone group, for example. It is reported that these resins exhibit a property of controlling alignment of liquid crystals (hereinafter, also called liquid crystal alignment properties) by polarized UV irradiation (see Patent Document 3 to Patent Document 5).